arch/powerpc/boot/addRamDisk.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <netinet/in.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <string.h>
   8 #include <elf.h>
   9
  10 #define ElfHeaderSize  (64 * 1024)
  11 #define ElfPages  (ElfHeaderSize / 4096)
  12 #define KERNELBASE (0xc000000000000000)
  13 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
  14
  15 struct addr_range {
  16         unsigned long long addr;
  17         unsigned long memsize;
  18         unsigned long offset;
  19 };
  20
  21 static int check_elf64(void *p, int size, struct addr_range *r)
  22 {
  23         Elf64_Ehdr *elf64 = p;
  24         Elf64_Phdr *elf64ph;
  25
  26         if (elf64->e_ident[EI_MAG0] != ELFMAG0 ||
  27             elf64->e_ident[EI_MAG1] != ELFMAG1 ||
  28             elf64->e_ident[EI_MAG2] != ELFMAG2 ||
  29             elf64->e_ident[EI_MAG3] != ELFMAG3 ||
  30             elf64->e_ident[EI_CLASS] != ELFCLASS64 ||
  31             elf64->e_ident[EI_DATA] != ELFDATA2MSB ||
  32             elf64->e_type != ET_EXEC || elf64->e_machine != EM_PPC64)
  33                 return 0;
  34
  35         if ((elf64->e_phoff + sizeof(Elf64_Phdr)) > size)
  36                 return 0;
  37
  38         elf64ph = (Elf64_Phdr *) ((unsigned long)elf64 +
  39                                   (unsigned long)elf64->e_phoff);
  40
  41         r->memsize = (unsigned long)elf64ph->p_memsz;
  42         r->offset = (unsigned long)elf64ph->p_offset;
  43         r->addr = (unsigned long long)elf64ph->p_vaddr;
  44
  45 #ifdef DEBUG
  46         printf("PPC64 ELF file, ph:\n");
  47         printf("p_type   0x%08x\n", elf64ph->p_type);
  48         printf("p_flags  0x%08x\n", elf64ph->p_flags);
  49         printf("p_offset 0x%016llx\n", elf64ph->p_offset);
  50         printf("p_vaddr  0x%016llx\n", elf64ph->p_vaddr);
  51         printf("p_paddr  0x%016llx\n", elf64ph->p_paddr);
  52         printf("p_filesz 0x%016llx\n", elf64ph->p_filesz);
  53         printf("p_memsz  0x%016llx\n", elf64ph->p_memsz);
  54         printf("p_align  0x%016llx\n", elf64ph->p_align);
  55         printf("... skipping 0x%08lx bytes of ELF header\n",
  56                (unsigned long)elf64ph->p_offset);
  57 #endif
  58
  59         return 64;
  60 }
  61 void get4k(FILE *file, char *buf )
  62 {
  63         unsigned j;
  64         unsigned num = fread(buf, 1, 4096, file);
  65         for ( j=num; j<4096; ++j )
  66                 buf[j] = 0;
  67 }
  68
  69 void put4k(FILE *file, char *buf )
  70 {
  71         fwrite(buf, 1, 4096, file);
  72 }
  73
  74 void death(const char *msg, FILE *fdesc, const char *fname)
  75 {
  76         fprintf(stderr, msg);
  77         fclose(fdesc);
  78         unlink(fname);
  79         exit(1);
  80 }
  81
  82 int main(int argc, char **argv)
  83 {
  84         char inbuf[4096];
  85         struct addr_range vmlinux;
  86         FILE *ramDisk;
  87         FILE *inputVmlinux;
  88         FILE *outputVmlinux;
  89
  90         char *rd_name, *lx_name, *out_name;
  91
  92         size_t i;
  93         unsigned long ramFileLen;
  94         unsigned long ramLen;
  95         unsigned long roundR;
  96         unsigned long offset_end;
  97
  98         unsigned long kernelLen;
  99         unsigned long actualKernelLen;
 100         unsigned long round;
 101         unsigned long roundedKernelLen;
 102         unsigned long ramStartOffs;
 103         unsigned long ramPages;
 104         unsigned long roundedKernelPages;
 105         unsigned long hvReleaseData;
 106         u_int32_t eyeCatcher = 0xc8a5d9c4;
 107         unsigned long naca;
 108         unsigned long xRamDisk;
 109         unsigned long xRamDiskSize;
 110         long padPages;
 111
 112
 113         if (argc < 2) {
 114                 fprintf(stderr, "Name of RAM disk file missing.\n");
 115                 exit(1);
 116         }
 117         rd_name = argv[1];
 118
 119         if (argc < 3) {
 120                 fprintf(stderr, "Name of vmlinux file missing.\n");
 121                 exit(1);
 122         }
 123         lx_name = argv[2];
 124
 125         if (argc < 4) {
 126                 fprintf(stderr, "Name of vmlinux output file missing.\n");
 127                 exit(1);
 128         }
 129         out_name = argv[3];
 130
 131
 132         ramDisk = fopen(rd_name, "r");
 133         if ( ! ramDisk ) {
 134                 fprintf(stderr, "RAM disk file \"%s\" failed to open.\n", rd_name);
 135                 exit(1);
 136         }
 137
 138         inputVmlinux = fopen(lx_name, "r");
 139         if ( ! inputVmlinux ) {
 140                 fprintf(stderr, "vmlinux file \"%s\" failed to open.\n", lx_name);
 141                 exit(1);
 142         }
 143
 144         outputVmlinux = fopen(out_name, "w+");
 145         if ( ! outputVmlinux ) {
 146                 fprintf(stderr, "output vmlinux file \"%s\" failed to open.\n", out_name);
 147                 exit(1);
 148         }
 149
 150         i = fread(inbuf, 1, sizeof(inbuf), inputVmlinux);
 151         if (i != sizeof(inbuf)) {
 152                 fprintf(stderr, "can not read vmlinux file %s: %u\n", lx_name, i);
 153                 exit(1);
 154         }
 155
 156         i = check_elf64(inbuf, sizeof(inbuf), &vmlinux);
 157         if (i == 0) {
 158                 fprintf(stderr, "You must have a linux kernel specified as argv[2]\n");
 159                 exit(1);
 160         }
 161
 162         /* Input Vmlinux file */
 163         fseek(inputVmlinux, 0, SEEK_END);
 164         kernelLen = ftell(inputVmlinux);
 165         fseek(inputVmlinux, 0, SEEK_SET);
 166         printf("kernel file size = %lu\n", kernelLen);
 167
 168         actualKernelLen = kernelLen - ElfHeaderSize;
 169
 170         printf("actual kernel length (minus ELF header) = %lu\n", actualKernelLen);
 171
 172         round = actualKernelLen % 4096;
 173         roundedKernelLen = actualKernelLen;
 174         if ( round )
 175                 roundedKernelLen += (4096 - round);
 176         printf("Vmlinux length rounded up to a 4k multiple = %ld/0x%lx \n", roundedKernelLen, roundedKernelLen);
 177         roundedKernelPages = roundedKernelLen / 4096;
 178         printf("Vmlinux pages to copy = %ld/0x%lx \n", roundedKernelPages, roundedKernelPages);
 179
 180         offset_end = _ALIGN_UP(vmlinux.memsize, 4096);
 181         /* calc how many pages we need to insert between the vmlinux and the start of the ram disk */
 182         padPages = offset_end/4096 - roundedKernelPages;
 183
 184         /* Check and see if the vmlinux is already larger than _end in System.map */
 185         if (padPages < 0) {
 186                 /* vmlinux is larger than _end - adjust the offset to the start of the embedded ram disk */
 187                 offset_end = roundedKernelLen;
 188                 printf("vmlinux is larger than _end indicates it needs to be - offset_end = %lx \n", offset_end);
 189                 padPages = 0;
 190                 printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 191         }
 192         else {
 193                 /* _end is larger than vmlinux - use the offset to _end that we calculated from the system map */
 194                 printf("vmlinux is smaller than _end indicates is needed - offset_end = %lx \n", offset_end);
 195                 printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 196         }
 197
 198
 199
 200         /* Input Ram Disk file */
 201         // Set the offset that the ram disk will be started at.
 202         ramStartOffs = offset_end;  /* determined from the input vmlinux file and the system map */
 203         printf("Ram Disk will start at offset = 0x%lx \n", ramStartOffs);
 204
 205         fseek(ramDisk, 0, SEEK_END);
 206         ramFileLen = ftell(ramDisk);
 207         fseek(ramDisk, 0, SEEK_SET);
 208         printf("%s file size = %ld/0x%lx \n", rd_name, ramFileLen, ramFileLen);
 209
 210         ramLen = ramFileLen;
 211
 212         roundR = 4096 - (ramLen % 4096);
 213         if ( roundR ) {
 214                 printf("Rounding RAM disk file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR);
 215                 ramLen += roundR;
 216         }
 217
 218         printf("Rounded RAM disk size is %ld/0x%lx \n", ramLen, ramLen);
 219         ramPages = ramLen / 4096;
 220         printf("RAM disk pages to copy = %ld/0x%lx\n", ramPages, ramPages);
 221
 222
 223
 224   // Copy 64K ELF header
 225         for (i=0; i<(ElfPages); ++i) {
 226                 get4k( inputVmlinux, inbuf );
 227                 put4k( outputVmlinux, inbuf );
 228         }
 229
 230         /* Copy the vmlinux (as full pages). */
 231         fseek(inputVmlinux, ElfHeaderSize, SEEK_SET);
 232         for ( i=0; i<roundedKernelPages; ++i ) {
 233                 get4k( inputVmlinux, inbuf );
 234                 put4k( outputVmlinux, inbuf );
 235         }
 236
 237         /* Insert pad pages (if appropriate) that are needed between */
 238         /* | the end of the vmlinux and the ram disk. */
 239         for (i=0; i<padPages; ++i) {
 240                 memset(inbuf, 0, 4096);
 241                 put4k(outputVmlinux, inbuf);
 242         }
 243
 244         /* Copy the ram disk (as full pages). */
 245         for ( i=0; i<ramPages; ++i ) {
 246                 get4k( ramDisk, inbuf );
 247                 put4k( outputVmlinux, inbuf );
 248         }
 249
 250         /* Close the input files */
 251         fclose(ramDisk);
 252         fclose(inputVmlinux);
 253         /* And flush the written output file */
 254         fflush(outputVmlinux);
 255
 256
 257
 258         /* Fixup the new vmlinux to contain the ram disk starting offset (xRamDisk) and the ram disk size (xRamDiskSize) */
 259         /* fseek to the hvReleaseData pointer */
 260         fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET);
 261         if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) {
 262                 death("Could not read hvReleaseData pointer\n", outputVmlinux, out_name);
 263         }
 264         hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */
 265         printf("hvReleaseData is at %08lx\n", hvReleaseData);
 266
 267         /* fseek to the hvReleaseData */
 268         fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET);
 269         if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) {
 270                 death("Could not read hvReleaseData\n", outputVmlinux, out_name);
 271         }
 272         /* Check hvReleaseData sanity */
 273         if (memcmp(inbuf, &eyeCatcher, 4) != 0) {
 274                 death("hvReleaseData is invalid\n", outputVmlinux, out_name);
 275         }
 276         /* Get the naca pointer */
 277         naca = ntohl(*((u_int32_t*) &inbuf[0x0C])) - KERNELBASE;
 278         printf("Naca is at offset 0x%lx \n", naca);
 279
 280         /* fseek to the naca */
 281         fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 282         if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) {
 283                 death("Could not read naca\n", outputVmlinux, out_name);
 284         }
 285         xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c]));
 286         xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14]));
 287         /* Make sure a RAM disk isn't already present */
 288         if ((xRamDisk != 0) || (xRamDiskSize != 0)) {
 289                 death("RAM disk is already attached to this kernel\n", outputVmlinux, out_name);
 290         }
 291         /* Fill in the values */
 292         *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs);
 293         *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages);
 294
 295         /* Write out the new naca */
 296         fflush(outputVmlinux);
 297         fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 298         if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) {
 299                 death("Could not write naca\n", outputVmlinux, out_name);
 300         }
 301         printf("Ram Disk of 0x%lx pages is attached to the kernel at offset 0x%08lx\n",
 302                ramPages, ramStartOffs);
 303
 304         /* Done */
 305         fclose(outputVmlinux);
 306         /* Set permission to executable */
 307         chmod(out_name, S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
 308
 309         return 0;
 310 }
 311